At present, in the existing OLED display device, a control signal is generally transmitted to the display device through such external circuits as flexible printed circuit (FPC), and the like, so that the FPC needs to be bonded with the OLED display device, namely, a golden finger on the FPC is bonded with a corresponding pad on the display device to transmit the signal from the FPC to the display device. Taking the OLED display device integrating a touch function as an example, FPC is firstly aligned to the OLED display device through a bonding mark to align the golden finger of the FPC to the pad on the substrate of the OLED display device, and then, the golden finger is bonded with the pad through a conductive glue.
However, in the prior art, the OLED display device is generally encapsulated by melting frit (also called encapsulation frit) coated on substrates of the OLED display device through laser irradiation to encapsulate the two substrates. The bonding mark for alignment of the FPC and the OLED display device is formed above the frit. We know that the frit needs to be welded by a laser in a welding process, so that the color of its material is deep or black to benefit light absorption. In addition, the material of the bonding mark is generally indium tin oxide (ITO) which is of high transmittance (about 97%) and low reflectivity (about 7%). Therefore, an optical camera is difficult to capture the bonding mark, thus failing to successfully complete the bonding process. Furthermore, the bonding mark is located above the black frit, which causes laser reflection in the laser irradiation process and results in fluctuation in heat absorption to affect the encapsulation effect.